Laminated films are known which are each provided with a thin film layer formed (laminated) on the surface of a substrate in order to impart functionality to a film-like substrate. For example, laminated films having gas barrier characteristics imparted by the formation of a thin film layer on a plastic film are suitable to the filling and packaging of products such as foods and drinks, cosmetics, and detergents. Laminated films have been recently proposed which have a structure in which a thin film of an inorganic oxide such as silicon oxide, silicon nitride, silicon oxynitride, or aluminum oxide is formed on one surface of a substrate film.
As a method for forming a thin film of an inorganic oxide on a surface of a plastic substrate in the above manner, film formation methods, for example, physical vapor deposition methods (PVD) such as a vacuum deposition method, sputtering method, ion plating method, and chemical vapor deposition methods (CVD) such as a low-pressure chemical vapor deposition method and plasma chemical vapor deposition method are known. Then, Patent Document 1 describes a gas barrier laminated film in which a thin film layer of silicon oxycarbide is formed by the above method.